Typha Leaf Research Articles

Physical properties, morphology and crystallinity of Typha leaf fibers processed by different extraction treatments

The effect of different extraction processes on the properties of Typha leaf fibers was investigated. In this work, manual decortications (FNT), NaOH alkali treatment (FT), sea water retting (FM) and a combined treatment (FC) including NaOH plus enzyme Pectinex Ultra SPL were compared. After the extraction process, morphological structure was examinated, physical and mechanical properties were also discussed. Scanning electron microscopy results revealed that extraction of Typha leaf fibers by NaOH plus enzyme led to removal of surface impurities and non-cellulosic materials. According to X-ray diffraction results, crystallinity index of (FC) was improved after enzymatic process by 57% compared to manual decorticated fibers. Tenacity of Typha fibers improved after different extraction methods when compared to manual decortications. Especially sea water retting process (FM) showed an increase of 82% higher tensile strength. Moreover, attenuated infrared spectroscopy analysis revealed that chemical retting, sea water process and combined treatment caused change of chemical composition by disappearing and/or attenuation of some bands which belong to hemicelluloses and lignin compounds. Also, chemical constituents’ analysis presents lignin fraction and alpha cellulose equal to 8.13% and 69.8% respectively for (FC).

Evaluation of water depth and inundation duration on Typha domingensis sustainability in the Everglades Stormwater treatment areas: A test cell study

Typha domingensis is a dominant plant species in the Everglades Stormwater Treatment Areas, freshwater wetlands constructed to reduce phosphorus (P) levels in stormwater runoff prior to discharge into the Everglades. Water depth and duration of inundation can negatively affect the health of these plants. To determine the effect of water depth and inundation duration, Typha plants were grown in this study in a series of 15 test cells, 0.2 ha in area, and exposed to five water-depth treatments over 10 months: control (40 cm), shallow (61 cm), moderate (84 cm), deep (104 cm) and extremely deep (124 cm). Mean adult Typha densities declined from 14.1 shoots m−2 in the control to 10.9 and 10.5 shoots m−2 in the deep and extremely-deep treatments, respectively. However, only mean juvenile Typha densities were significantly different among water-level treatments, declining from 3.2 juveniles m−2 in the control to 1.2 and 0.6 juveniles m−2 in the deep and extremely-deep treatments, respectively. Typha leaf elongation rate (LER) was significantly higher in the deeper treatments, with the highest rates measured during the active growing season (July to October). LER increased from 6.84 cm day−1 during June baseline measurements to 8.89 cm day−1 in the deeper treatments after eight weeks of continuous inundation. Typha showed morphological plasticity to adapt to deep water through changes in morphology and biomass allocation. Typha grew significantly taller and heavier to adapt to deep-water conditions and facilitate gas exchange between the above and belowground tissues. Ramet height of Typha harvested at the end of the study averaged 343 and 374 cm in the deep and extremely-deep treatments, respectively, compared to 285 cm in the control. Likewise, the weight of individual adult ramets was significantly greater in the deeper treatments (256 g ramet−1) compared to the control (123 g ramet−1). Although none of the water-level treatments resulted in a total collapse of their Typha populations, increased LER in the deeper treatments resulted in less structural support in stems, causing substantial Typha lodging when water levels were lowered at the end of the study. These findings provide valuable insight into the effect of different water-level inundations on plant responses and overall health of Typha populations in the STAs.

Study of thermal and mechanical properties of typha leaf - clay panels

Study of thermal and mechanical properties of typha leaf - clay panels

Tailoring the Effective Properties of Typha Fiber Reinforced Polymer Composite via Alkali Treatment

Typha fibers were chemically retted in 5% sodium hydroxide solution for 1 h, 2 h, 4 h, and 8 h. Changes in chemical compositions of the untreated and treated fibers were monitored with Fourier transmission infrared spectroscopy, while changes in the crystallinity index were studied via X-ray diffraction. The FTIR spectra and scanning electron microscope images corroborated the successful removal of amorphous portions from the Typha leaf fibers during alkali treatment, which resulted in an enhanced crystallinity index for alkali-treated fibers. The alkali-treated Typha fiber for 1 h showed the highest water contact angle of 87.5°, while the untreated composite showed the lowest contact angle. Typha fiber treated for 4 h had high tensile strength, Young’s modulus, and elongation at break of 158 MPa, 1600 MPa, and 7%, respectively. The results showed that there was a general increase in the interfacial shear strength of Typha fiber with epoxy resin and polyester resin with increased time. Both the mechanical properties and crystallinity index of the Typha leaf fibers increased with increased time of retting until 4 h, after which further alkaline retting resulted in decreased values. The overall results showed that alkaline-extracted Typha leaf fibers are suitable for biodegradable film composites.

Effects of ferric sulfate and polyaluminum chloride coagulation enhanced treatment wetlands on Typha growth, soil and water chemistry

Land surface subsidence is a concern in many deltas worldwide as it contributes to water quality degradation, loss of fertile land and increased potential for levee failure. As a possible solution to these concerns, on-site coagulation enhanced treatment wetlands (CETWs), coagulation water treatment followed by wetland passage serving as a settling basin, were implemented in a field-scale study located on a subsided island of the Sacramento-San Joaquin Delta in northern California under three treatments; coagulation with polyaluminum chloride (PAC), coagulation with ferric sulfate and an untreated control. Because CETWs offer a relatively novel solution for water quality improvement and subsidence reversal due to its low-infrastructure requirements and in-situ nature, effects from these systems remain uncharted and they may have adverse effects on plant biomass production that also contribute to sediment accretion. This study focuses on the effect CETWs had on the growth of Typha spp.; the dominant vegetation in the wetlands. Plant growth parameters and nutrient content were measured in conjunction with soil, pore water and surface water chemistry. Soil analysis indicated there was no intermixing of newly formed flocs and original soil material. Where there was significant deposition of floc, PAC treatment reduced phosphate concentrations and ferric sulfate treatment increased total Fe concentrations in surrounding water compared to the control. Results indicated coagulation treatments had no negative effects on Typha leaf nutrient content, Typha growth or allometric parameters. Additionally, no signs of plant toxicity such as necrosis, wilting or chlorosis were observed in any of the treatments. Overall, this study suggests that CETWs are viable treatment option for water quality improvement and sediment accretion while having no negative impact on the growth of Typha plants.

Experimental study and numerical simulation on the structural and mechanical properties of Typha leaves through multimodal microscopy approaches

The Typha leaf, with special multi-level structure, low density and excellent mechanical properties, is an ideal bionic prototype utilized for lightweight design. In order to further study the relationship between the structure and mechanical properties, the three-dimensional macroscopic morphology of Typha leaves was characterized by micro computed tomography (Micro-CT) and its internal microstructure was observed by scanning electron microscopy (SEM). The combination of experimental and computational research was carried out in this paper, to reveal and verify the effect of multi-level structure on the mechanical properties. A universal testing machine and a self-developed mechanical testing apparatus with high precision and low load were used to measure the mechanical properties of the axial compression and lateral bending of the leaves, respectively. Three models with different internal structures were established based on the above-mentioned three-dimensional morphologies. The result demonstrated that the structure of partitions and diaphragms within the Typha leaf could form a reinforcement ribs structure which could provide multiple load paths and make the process of compression and bending difficult. The further nonlinear finite element analysis through LS-DYNA proved that internal structure could improve the ability of the models to resist compression and deformation. The investigation can be the reference for lightweight thin-walled structure design and inspire the application of the bionic structural materials.

The Structure and Flexural Properties of Typha Leaves.

The Typha leaf has a structure of lightweight cantilever beam, exhibiting excellent mechanical properties with low density. Especially, the leaf blade evolved high strength and low density with high porosity. In this paper, the structure of Typha leaf was characterized by microcomputed tomography (Micro-CT) and scanning electron microscopy (SEM), and the relationship with flexural properties was analyzed. The three-point bending test was performed on leaves to examine flexural properties, which indicated that the flexural properties vary from the base to the apex in gradient. The cross-sectional geometry shape of the leaf blade presented a strong influence on the optimized flexural stiffness. The load carrying capacity of the leaf depended on the development level of the epidermal tissue, the vascular bundle, the mechanical tissue, and the geometric properties. The investigation can be the basis for lightweight structure design and the application in the bionic engineering field.

Flexural properties of typha natural fiber-reinforced polyester composites

The effect of fiber treatment, reinforcement structure and fiber weight ratio on the flexural properties of Typha-polyester composites was studied. A unsaturated polyester matrix reinforced with a mixture of Typha Leaf fibers (M.Ty.LF) and a nonwoven Typha Leaf fibers (NW.Ty.LF) was fabricated with various treatments conditions (sea water, alkali and combined treatment) and fiber weight ratio. Results show that alkali treatment and combined process provided better mechanical properties of composites in comparison with fiber treated by sea water. The fiber weight ratio influenced the flexural properties of composites. Indeed, a maximum value of flexural strength (69.8 MPa) and flexural modulus (6.16 GPa) was observed for 12.6 % fiber weight ratio. SEM photographs revealed a different fracture surface between Typha Leaf fibers reinforced polyester composites.

Fungal contributions to carbon flow and nutrient cycling during decomposition of standing Typha domingensis leaves in a subtropical freshwater marsh

Summary Despite the well‐known occurrence of ‘standing‐dead’ emergent plant litter in freshwater marshes, the role of fungi in its decomposition is poorly known. Here, we quantified the growth and biomass dynamics of fungi associated with standing‐dead Typha domingensis leaves, estimated the contribution of fungi to carbon flow during decomposition and assessed their contribution to nutrient (nitrogen and phosphorus) cycling. In a subtropical freshwater marsh, standing leaves of T. domingensis were sampled in August while living (green) and then monthly during leaf senescence and standing‐dead decomposition for 1 year. Leaf samples were analysed for mass loss, fungal biomass (ergosterol), rates of fungal production (14C‐acetate incorporation) and microbial respiration (CO2 evolution), and for litter chitin (glucosamine), carbon, N and P concentrations. Losses in T. domingensis leaf carbon (37%) occurred during senescence and standing decomposition. During this time, increases in ergosterol and chitin concentrations were observed in the standing litter, indicating the rapid colonisation of decaying Typha leaves by fungi. Estimated fungal biomass (from ergosterol) reached a maximum of 37 mg C g−1 detrital C. Over the entire study period, estimated cumulative fungal production in standing Typha litter was 39 mg C g−1 initial detrital C, indicating that 11% of leaf C was converted to fungal C. The corresponding estimate of cumulative microbial respiration was 136 mg C g−1 initial detrital C, indicating that 37% of Typha leaf litter C was mineralised by microorganisms (bacteria and fungi) during decomposition. Fungi also immobilised up to c.27% and c.55% of the total detrital N and P, respectively. Fungi play an important role in the cycling of C and nutrients in freshwater marshes, and this should be integrated into current models that describe major biogeochemical pathways.

Fibre cables in the lacunae of Typha leaves contribute to a tensegrity structure

Cables composed of long, non-lignified fibre cells enclosed in a cover of much shorter thin-walled, crystal-containing cells traverse the air chambers (lacunae) in leaves of the taller species of Typha. The non-lignified fibre cables are anchored in diaphragms composed of stellate cells of aerenchyma tissue that segment the long air chambers into smaller compartments. Although the fibre cables are easily observed and can be pulled free from the porous-to-air diaphragms, their structure and function have been ignored or misinterpreted. Leaves of various species of Typha were dissected and fibre cables were pulled free and observed with a microscope using bright-field and polarizing optics. Maximal tensile strength of freshly removed cables was measured by hanging weights from fibre cables, and Instron analysis was used to produce curves of load versus extension until cables broke. Polarized light microscopy revealed that the cellulose microfibrils that make up the walls of the cable fibres are oriented parallel to the long axis of the fibres. This orientation ensures that the fibre cables are mechanically stiff and strong under tension. Accordingly, the measured stiffness and tensile strength of the fibre cables were in the gigapascal range. In combination with the dorsal and ventral leaf surfaces and partitions that contain lignified fibre bundles and vascular strands that are strong in compression, the very fine fibre cables that are strong under tension form a tensegrity structure. The tensegrity structure creates multiple load paths through which stresses are redistributed throughout the 1-3 m tall upright leaves of Typha angustifolia, T. latifolia, T. × glauca, T. domingensis and T. shuttleworthii. The length of the fibre cables relative to the length of the leaf blades is reduced in the last-formed leaves of flowering individuals. Fibre cables are absent in the shorter leaves of Typha minima and, if present, only extend for a few centimetres from the sheath into the leaf blade of Typha laxmannii. The advantage of the structure of the Typha leaf blade, which enables stiffness to give way to flexibility under windy conditions, is discussed for both vegetative and flowering plants.

Photosynthetic acclimation within individual Typha latifolia leaf segments

Growing Typha latifolia leaf segments traverse a wide range of light environments as they are pushed upward from basal meristems through sediment, water, and dense litter and leaf layers. We used light transfer experiments in a greenhouse to investigate the photosynthetic acclimation of individual Typha leaf segments. Fully expanded leaf segments exhibited strong and symmetrical acclimation to increases or decreases in light. The photosynthetic light response curves of shade grown segments that were transferred to high light acclimated within 10–15 days to match those of segments that grew and remained in high light. Acclimation was highly localized; the light response curves of shade grown segments that remained shaded did not change, even as adjacent segments acclimated to high light. Leaf segments exposed to various treatments did not differ significantly in leaf mass per area; Typha leaves are apparently morphologically preformed to function in high light and allow high photosynthetic capacity, regardless of the growth environment. Likewise, nitrogen content did not differ significantly between treatments, and photosynthetic acclimation may involve a reallocation or activation of nitrogen within a leaf segment, rather than a net nitrogen translocation into or out of a segment. We interpret these patterns as an adaptive strategy that maximizes carbon gain by monocot leaves growing in a vertically heterogeneous light environment

Contributions of fungi to carbon flow and nutrient cycling from standing dead Typha angustifolia leaf litter in a temperate freshwater marsh

Standing dead plant litter often constitutes a large fraction of the detritus in many freshwater marshes and lake littoral habitats. Despite this evidence, microbial decay processes in standing litter and its contribution to wetland carbon and nutrient cycling have rarely been quantified. We examined the contribution of fungi to carbon flow and nutrient cycling from Typha angustifolia during senescence and standing litter decomposition. Naturally standing Typha leaves were collected in August and then periodically over 1 yr. We quantified losses in leaf carbon (C), fungal biomass, and fungal production rates and constructed a partial budget estimating C flow into fungal decomposers. Additionally, we determined leaf litter N and P concentrations to assess the effect of fungi on detrital nutrient dynamics. Significant losses in leaf C occurred during plant senescence and standing litter decay (∼ 55%). Fungal biomass increased during litter decay, reaching a maximum of 106 ± 7 mg C g−1 detrital C. Cumulative fungal production totaled 123 mg C g−1 initial detrital C, indicating that 22% of the Typha leaf C lost was assimilated into fungal biomass. Fungi also transformed and immobilized nutrients within Typha leaves, with fungal N and P accounting for > 50% of the total detrital N and P during later stages of leaf decay. Significant transformation and decomposition of emergent macrophyte litter occurs during the standing dead phase, and a large portion of the plant C and nutrients are channeled into and through fungal decomposers.

Typha domingensis leaf powder for decontamination of aluminium, iron, zinc and lead: Biosorption kinetics and equilibrium modeling

The present study explores the effectiveness of Typha domingensis leaf powder for simultaneous removal of aluminium, iron, zinc and lead ions from aqueous solution. Batch experiments were carried out in laboratory at room temperature and at initial ions concentrations simulating the concentrations of these cations in real wastewater samples. The sorption process was examined applying the first and second order kinetic mechanisms. The results were best described by the second order rate kinetics. The applicability of the three equilibrium isotherm models was investigated. The obtained data follow the three investigated isothermal models in the following order: Langmuir > Freundlich > Temkin, for all the studied metal ions. The infrared spectra of native and exhausted Typha leaf powder confirmed ions-biomass interactions responsible for sorption. The results showed that Typha domingensis leaf powder can easily be envisaged as a new low cost natural biosorbent for metal clean up operations in aquatic systems.

Phosphorus uptake by Typha leaf litter as affected by oxygen availability

ABSTRACT Soluble reactive phosphorus (SRP) concentrations in wetland surface waters were measured during laboratory incubations in the presence of wetland soils and Typha leaf litter. Aerated water columns above intact soil cores increased in SRP concentration (up to 73 µg L−1) over 28 days, whereas the water column in cores containing soil and a Typha litter layer showed no concentration increase (remained < 5 µg SRP L−1). In the absence of soil, phosphorus (P) uptake by leaf litter and associated microbial biomass occurred rapidly under oxic conditions (max. 24-hr. uptake, 524 ± 90 µg P g−1 dry litter d−1), but uptake was slower and less complete under hypoxic conditions. At the highest tested initial P concentration of 1 mg L−1, P uptake by litter under hypoxic conditions (< 0.5 mg O2 L−1) was 41% of the oxic rate, or 216 ± 42 µg P g−1 dry litter d−1. Differences between hypoxic and oxic P uptake rates, however, were not observed at initial SRP concentrations of 100 µg L−1 or less. Our results suggest ...

Evaluation of the efficacy of the photosystem II inhibitor DCMU in periphyton and its effects on nontarget microorganisms and extracellular enzymatic reactions

AbstractWe examined the efficacy of the photosystem II inhibitor 3-(3,4-diclorophenyl)-1,1-dimethyl urea (DCMU) for inhibition of algal photosynthesis in periphyton associated with submerged decomposing litter of Typha angustifolia. We also investigated the possible nontarget effects of DCMU exposure on heterotrophic microorganisms (i.e., bacteria and fungi) and extracellular enzyme activity associated with decaying litter. Standing-dead Typha leaf litter was submerged for 34 and 73 d, returned to the laboratory, and used for controlled laboratory experiments that examined the effect of DCMU on algal ([14C]bicarbonate, pulse-amplitude modulated fluorometry), bacterial ([3H]leucine), and fungal ([14C]acetate) production. Simultaneous assays also were conducted to examine the effect of DCMU on the activities of 4 extracellular enzymes (β-glucosidase, β-xylosidase, leucine-aminopeptidase, and phosphatase). DCMU significantly inhibited algal photosynthesis in light-exposed periphyton (p always < 0.0003), with...

Periphytic Photosynthetic Stimulation of Extracellular Enzyme Activity in Aquatic Microbial Communities Associated with Decaying Typha Litter

We examined the effect of light on extracellular enzyme activities of periphytic/endogenous microbial assemblages associated with decomposing litter of an emergent macrophyte Typha angustifolia within a small inland wetland in southeastern Michigan. Standing-dead Typha leaf litter was collected, placed into floating wire mesh litter baskets, and submerged in a wetland pool. Enzyme saturation assays were conducted on three occasions following litter submergence (days 9, 28, and 44) to generate saturation curves for the individual enzymes tested and to examine potential differences in enzyme saturation kinetics during microbial colonization and development. Experimental light manipulations were conducted on two occasions during microbial development (days 10 and 29). Short-term (30 min) light exposure significantly increased extracellular beta-glucosidase activity of litter-associated microbial communities. Activities of beta-xylosidase and leucine-aminopeptidase were not stimulated, and stimulation of phosphatase activity was variable. The exact mechanism for increased enzyme activity remains unknown, but it may have been increased pH arising from periphytic algal photosynthesis. These results suggest that extracellular enzyme activity in microbial communities colonizing natural organic substrata may be influenced by light/photosynthesis, as has previously been demonstrated for periphyton communities grown on artificial, inert substrata. Thus, light/photosynthetic mediated stimulation of extracellular enzyme activities may be a common occurrence in microbial communities associated with natural decaying plant litter in wetlands and might engender diurnal patterns in other microbial decay processes (e.g., production, organic matter decomposition, and mineralization).